The compound tropenol is known from the prior art and has the following chemical structure:

The compound may be used as a starting compound for preparing pharmacologically valuable compounds. For example, the compounds tiotropium bromide, ipratropium bromide or also BEA2108 may be mentioned in this context. These pharmacologically valuable substances are characterized by the following chemical structures:

Because of the high degree of efficacy of the above compounds they have to be made available in as pure form as possible using efficient methods of synthesis. The stringent purity requirements, in particular, with which compounds intended for therapeutic use generally have to comply, demand the lowest possible levels of contaminant in the starting compounds. If materials which contain relatively high levels of impurities are used as starting compounds, purification of the end product is often difficult as any impurities introduced at the beginning often cannot easily be removed at later stages of synthesis or only at the expense of substantial losses of yield. This is particularly the case when the by-products or impurities present only differ slightly structurally from the main products in question.
Against this background the problem of the present invention is to provide a method of synthesis which allows industrial production of tropenol, preferably in the form of one of the acid addition salts thereof, in a good yield and particularly with a high degree of purity.